Lifting jack



April 3, 1928. 1,664,579

B w. TWYMAN LI FTING JACK Filed June a, 1925 2 Sheets-Sheet l INVEN TOR. B Wick/177k Thy/776)? Patented Apr. 3, 1928.

UNITED STATES PATENT OFFICE.

B WICKLIFI'E TWYKAN, OF KAIBYSVILLE, MICHIGAN.

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Application filed June 8, 1925. Serial No. 35,894.

My invention relates to im rovements in lifting jacks and particular y to lift-ing jacks for automobiles.

My jack is especially designed for use 1n connection with automobiles equipped with the balloon tire, and oneof the objects of my invention is to provide a jack which may be lowered to be readil slipped under an automobilewhen the ba oon tire is deflated and which will give sufiicient lift to fully clear the tire from the ground.

Another object of my invention is to provide a jack of the lazy tong or toggle type which may be cheaply manufactured and which at the same time will possess sufiicient rigidity to prevent tilting.

For the purpose of disclosing my invention I have illustrated certain embodiments thereof in the accompanying drawings in which Fig. 1 is a side elevation of a jack embod mg my invention;

ig. 2 is an end elevation thereof;

Fig. 3 is a sectional view on the line 33 of Fig. 2; i

Fig. 4 is a detail section on the line 44 of Fig. 3;

Fig. 5 is a detail section on the line 55 of F1g. 1;

Fig. 6 is a of Fig. 1;

Fig. 7 is a side elevation of a modification, and

Fig. 8 is an end elevation thereof.

In the structure illustrated I provide a toggle structure comprising the upper toggles 1 and 2 and the lower toggles 3 and 4 which are jointed at their knuckles by pivot pins 5.

The upper ends of the toggles 1 and 2 cross one another and at the point of cross ing are pivoted together by a pivot pin 6. Resting on the tops of the crossed toggles 1 and 2 is a saddle 7 provided with a downwardly extendin vertical guide plate 8 which is provide with an elongated slot 9 and through which passes the pivot pin 6. Suitable washers 10' are provided on each detail section on the line 66 end of the pivot pin for preventing the sep aration of the parts.

The ends of the lower toggles 3 and 4 are likewise crossed and pivoted together at the crossing point by a pivotpin 11. These toggles work between a pair of vertical standards 12 and 13 which are provided with horizontally disposed arms 14 and 15 and 2 and the ends of the lower toggles 3 v and 4, respectively, engage the top saddle 7 and the base 16 when the pins 6 and 11 reach the limits of the slots 9 and 17, further movement of the jack in raisin direction isprevented so that the togg es will be maintained slightly spread apart and in a position to be lowered. This prevents the toggles from getting on dead center. It will also be noted that that portion of the ends of the-toggles, both upper and lower, which engage respectively the saddle 7 and the base 16 are rounded on their inner corners as at 18 to permit them to readily rotate and slide on their saddle and base and when the jack is raised the straight portion 19 on the top and bottom of the toggles provides a wide bearing surface.

The toggles are expanded and collapsed by means of a screw 20 having one end stationarily secured with respect to one of the knuckles of the toggle and the other operating in a nut connected to the opposite knuckle. For mounting the screw I provide a substantially rectangular sheet metal trunnion member one side 21 of which fits between the knuckle ends of the toggles 1 and 4, the pivot 5 securing the same in position. Extendin at right angles to the side 21 is an end p ate 23 having an opening to receive the screw 20 and an opposite end plate 24 is connected to the end plate 23 by a side 25. This end plate is also provided with an opening to receive the screw 20. This arrangement provides fora sheet metal bearing which, while being secured only by the pivot 5 is prevented from tilting and thereby tending to bind on the screw. The opposite trunnion member is substantially like that illustrated in Fig. 4 with the exception that a. bushing or collar 26 is secured between the two end walls 23 and 24 to-receive the end of the screw and this end is pinned by a pin 27 against rotation. Y

O crating on the screw 20 is a nut 28 in the orm of a ear which meshes with a pinion 29 mounted on a stub shaft 30 rotatable in an extension arm 31 of the end wall 23. This stub shaft 30 is provided with a squared end 32 to receive a suitable driving Wrench and it willbe noted that as the pinion 29 is rotated it in turn rotates the gear 28 expanding and collapsing the toggle.

In the structure illustrated in Figs. 7 and 8 one of the lower toggles is pivotally connected to the base 16 between a pair of ears 33 extending upwardly from the base and one of the upper tog les is pivotall connected to the plate 8 y a pin 34, t ereby dispensing with the slots 9 and 17 as inthe structure illustrated in F igs.' l to 6.

I claim as In invention:

In a liftingack the combination with a fiat base plate having a vertically disposed lug thereon, of a pair of crossed arms having their lower ends pivotally connected at their crossing point and having their lower ends rounded and bearing on said base plate, said vertically extending lug preventing said arms from tilting from the vertical, a pair of upper crossed arms pivotally connected at their crossing point and -having their 5 one of'each pair of arms and having a 30 threaded connection at the pivotal juncture, of the opposite arms, a saddle block resting upon the free ends of the upper crossed arms and havin a down turned side member provided Wifil nectmg the same with the crossed arms wllilile permitting the block to move vertica Iii witness whereof, I, B WICKLIFFE TwY- MAN, have hereunto set my hand at Indian- 40 apolis, Indiana, this 4th day of June, A. D. one thousand nine hundred and twenty five.

B WICKLIFFE TWYMAN.

connecting means for con- 35 

